Method for producing an annular element comprising an inner toothing, especially a sliding sleeve, and device for carrying out the method

ABSTRACT

A method for producing an annular element having an inner toothing, especially a sliding sleeve. An outlet ring element can be arranged in an extrusion device which includes an annular matrix element with an inner bore hole, a sleeve stamping device which is arranged therein and has first and second annular sleeve stamping elements which can be moved in relation to each other in the inner bore hole, and an inner stamping device having first and second inner stamping elements and first and second partial regions which are interspaced in the circumferential direction. When the inner stamping device is closed, the partial regions form cavities for producing the inner toothing. The outlet ring element is arranged between the first and second inner stamping elements and is measured in such a way that when closing the sleeve stamping device, material from the outlet ring element flows into the cavities for the formation of the inner toothing.

This is a nationalization of PCT/DE03/01005 filed Mar. 26, 2003 andpublished in German.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for producing an annularelement comprising an inner toothing, especially a sliding sleevewherein an outlet ring element can be arranged in an extrusion device.

2. Desscription of the Related Art

DE 198 20 645 A1 discloses a method in which the sleeve body of asliding sleeve is manufactured in one piece in a non-cutting processfrom sheet metal with one break at the outer perimeter and with an innertoothing at the inner perimeter. The gear shift fork guide is in theform of two rings that are affixed at the break. One problem with such aproduction method consists in the fact that the design process iscomparatively complex and therefore expensive. The same is also true ofprior arts of metal-cutting manufacturing methods.

SUMMARY OF THE INVENTION

The task of the present invention consists of creating a method thatenables the relatively simple and therefore inexpensive production of anannular element with inner toothing, especially a sliding sleeve.

This task is solved by a method according to the present invention forproducing an annular element comprising an inner toothing, especially asliding sleeve, wherein an outlet ring element can be arranged in anextrusion device which includes an annular matrix element with an innerbore hole, a sleeve stamping device which is arranged therein having afirst and a second annular sleeve stamping element which can be moved inrelation to each other in the inner bore hole, and an inner stampingdevice having a first and a second inner stamping element and first andsecond partial regions which are interspaced in the circumferentialdirection. When the inner stamping device is closed, the partial regionsform cavities for producing the inner toothing. The outlet ring elementis arranged between the first and second inner stamping elements and ismeasured in such a way that when closing the sleeve stamping device,material from the outlet ring element flows into the cavities for theformation of the inner toothing.

The main advantage therefore consists in that the method according tothe present invention enables the production of annular elements with aninner toothing, especially that of sliding sleeves, by means of lateralextrusion. In one advantageous embodiment the straight-cut toothings aswell as the laterally adjacent roof-shaped toothings of the innertoothing. Complex process steps required for the production of suchannular elements with inner toothing by means of rolling (separate stepsfor the production of straight-cut toothing and roof-shaped toothing)could therefore be eliminated. In the same way the known anddisadvantageous process steps of a non-cutting technology are notrequired.

One advantage of the method according to the present invention is thefact that the lateral extrusion can take place automatically on anappropriately designed lateral extrusion device equipped with theappropriately dimensioned outlet ring element.

In one embodiment of the present invention, undercuts are produced inthe inner toothing using an additional extrusion device, as they arecommonly found for instance in sliding sleeves. These undercuts arecomparatively simple to make and can also be produced automatically.

Advantageous embodiments of the invention arise from the subordinateclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventions and their embodiments are explained in more detail belowin connection with the following figures, in which:

FIG. 1 shows the frontal view of a sliding sleeve produced using themethod in accordance with the present invention;

FIG. 2 shows an enlarged view of a section II—II in circumferentialdirection of two neighboring teeth of the inner toothing;

FIG. 3 shows a longitudinal top view of part of a section of a tooth ofthe inner toothing;

FIG. 4 shows a side view of the sliding sleeve shown in FIG. 1 producedusing the method in accordance with the present invention;

FIG. 5 shows a cross-section through an outlet ring element inaccordance with the present invention for the production of a ringelement with an inner toothing;

FIG. 6A shows a diagram of a lateral extrusion device for carrying outlateral extrusion for the production of the inner toothing according tothe method of the present invention, wherein the state shown in thisfigure is before lateral extrusion has taken place;

FIG. 6B shows the lateral extrusion device of FIG. 6A, wherein the stateshown in this figure is after the lateral extrusion has taken place; and

FIG. 7, 8 show an additional extrusion device for the production of atleast one undercut in the toothing elements of the inner toothingaccording to an improvement of the method revealed in the presentinvention;

FIG. 8 shows an improvement of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

The following considerations led to the present invention. The complexprocess steps using methods of prior art for producing a ring elementwith inner toothing, for instance a sliding sleeve according to FIG. 1to 4, can be avoided if the ring element with inner toothing is producedby means of lateral extrusion.

FIG. 1 to 4 show a sliding sleeve 1 produced in accordance with thepresent method. The sliding sleeve 1 basically consists of an annularelement 3 to which the individual axially running teeth elements 5 areformed on an inner toothing. On the outside, the body 3 may exhibitannular gear switching protrusions 7 that are interspaced from thesliding sleeve 1 in an axial direction and allow the sliding sleeve 1 toshift in an axial direction. These gear switching protrusions could beproduced for instance by means of a metal cutting procedure.

FIG. 2 shows a section II—II in a circumferential direction through twoneighboring toothing elements 5 of FIG. 1. FIG. 3 shows in section apart of the top view III—III of a tooth element 5. It can be seen thatthe front of each tooth element 5 has two lateral bevels 9′ and onebevel 9″ running inwards and upwards. When the sliding sleeve 1 is slidinto the lengthwise toothing (key slots) of a sleeve not shown here,these bevels 9′ and 9″ serve as a so-called insertion bevel. As shown inFIG. 3, the toothing elements 5 may possess undercuts 11 that serve gearswitching purposes.

The outlet ring element 10 is in the form of a forged blank that haspreferably been blasted and annealed.

As shown in FIG. 6A, the outlet ring element 10 is inserted into anextrusion device 90 that essentially consists of a matrix element 13furnished with an inner bore hole 12 and a sleeve stamping devicearranged therein comprising an upper sleeve stamping element 15 and alower sleeve stamping element 17, and an inner stamping devicecomprising an upper inner stamping element 19 and a lower inner stampingelement 21. The upper inner stamping element 19 and the lower innerstamping element 21 can be moved in an axial direction in a bore hole 20of the upper sleeve stamp 15 and a bore hole 18 of the lower sleevestamp 17. In the closed position, the upper inner stamping element 19and the lower inner stamping element 21 form cavities 27 arranged nextto each other in the circumferential direction, in which the individualtoothing elements 5 of the inner toothing are produced during theextrusion process. In the closed position, the upper inner stampingelement 19 and the lower inner stamping element 21 become meshed via atooth system 23, which forces the upper inner stamping element 19 andthe lower inner stamping element 21 to align exactly in the axialdirection and especially also in the circumferential direction, so thatin the closed position the aforementioned cavities 27 can be exactlyformed when the partial regions 27′, 27″ are moved next to one another.Namely, when viewed in the axial direction, each cavity 27 consists of afirst partial region 27′ arranged in the lower inner stamping element 21followed by a second partial region 27″ arranged in the upper innerstamping element 19.

The cavity 27 between the upper inner stamping element 19 and the lowerinner stamping element 21 is preferably divided in such way that thefirst partial region 27′ serves to form a roof-shaped toothing 9′, 9″ ofa tooth element 5 and the second partial region 27″ serves to form astraight-cut tooth and the other roof-shaped toothing of the individualtoothing elements 5 of the inner toothing. One advantage of this designis that during lateral extrusion, possible burrs do not develop in thearea of the straight-cut toothing but at the transition between thestraight-cut toothing and roof-shaped toothing, where an undercut iscreated later in a method explained in more detail down.

The annular pressing surfaces 16 of the upper sleeve stamping element 15and the lower sleeve stamping element 17 run diagonally to thelongitudinal axis LA of the extrusion device 90.

As shown in FIG. 5 it is assumed that when producing an annular element1 comprising an inner toothing in accordance with the present invention,for instance a sliding sleeve, it is assumed that said annular element 1has an outlet ring element 10 with an inner diameter Di, an outerdiameter Da, a radial thickness D and an axial length L1. The dottedline in FIG. 5 shows the length L2 to which the outlet ring element 10is shortened during the extrusion process, whereby the extruded materialvolume flows into the cavity 27 in order to form the toothing elements 5of the inner toothing. This will be described in more detail below inconnection with FIG. 6B.

The extrusion device 90 described above is processed in the followingmanner. First the outlet ring element 10 of FIG. 5 is inserted betweenthe upper sleeve stamping element 15 and the lower sleeve stampingelement 17 so that the annular pressing surfaces 16 of said sleevestamping elements lie against the upper or lower front side of theoutlet ring element 10. During this process, the inner stamping elements19, 21 are closed or are already closed, whereby they are pressedagainst each other with the force P2 of hydraulic pre-tension, wherebythe cavity 27 for the production of the toothing elements 5 is formed.The outer matrix element 13 preferably remains static in its position.

As shown in FIG. 6B, the inner stamping elements 15, 17 are now movedtowards one another by a force P1, whereby the lower inner stampingelement 17 preferably remains static in its position and the upper innerstamping element 15 is moved. In this process the length L1 of theoutlet ring element 10 is shortened to the length L2 of the annularelement 1, whereby the material volume of the outlet ring element 10corresponding to said shortened length “flows” or is pressed in thedirection of arrows F into the cavity 27 to form the toothing elements 5of the inner toothing.

The extrusion can be executed at a temperature that is preferablybetween ambient temperature and approximately 1200° C., especiallybetween about 1000° C. and 1200° C.

Since the extrusion causes an overflow of material and burrs, they willbe removed by deburring. Phosphate layers and rust will be removed bymeans of debonders.

As shown in FIG. 3, the production of undercuts 11 in the toothingelements 5 of the inner toothing according to an improvement of thepresent method are explained in more detail below in connection withFIG. 7.

For this purpose an additional extrusion device 100 is used, saidextrusion device 100 essentially consisting of a matrix element 101 withan ejector 102 and an ironing area 107, a stamping element 103 withmultiple divisions in the circumferential direction that concentricallysurround a die insert 105, and a pressing element 109.

The individual annulus elements 104 of the stamping element 103 arrangedin the circumferential direction as shown in FIG. 8 can be moved in aradial direction. For this purpose the upper ends of said annuluselements that are turned away from the matrix element 101 can be movedradially and are positioned in a retainer ring element 111 that is inturn affixed in a annular element 113 surrounding the die insert 105above the stamping element 103. The retainer ring element 111 with aninternal thread 114 of a protruding area 116 jutting out axially abovethe stamping element 103 is preferably screwed together onto an externalthread 117 of the annular element 113. On its side facing away from thematrix element 101, the annular element 113 features a flange element119 protruding radially and overlapping with the protruding area, saidflange element 119 being supported by a lateral annular element 120surrounding the die insert 103, said lateral annular element runningradially outwards from the die insert 103 and overlapping the flangeelement 120 radially. The flange element 119 and the lateral ringelement 120 become meshed together by means of a radial toothing 121,that serves to precisely align the elements 119, 116, and 103 in thecircumferential direction with regards to the elements 120 and 105 andto position them correctly.

The retainer ring element 111 is preferable provided with guide pins 125running in a radial direction, that mesh into the corresponding radiallyrunning bore holes 127 of the upper area of the annulus element 104 ofthe stamping elements 103.

The outer surface of the lateral ring element 120 meshes into a borehole of the already mentioned pressing element 109 and is affixed to thesame, wherein an axial area 130 of the pressing element 109 runs axiallydownwards in the direction of the matrix element 101 and rests againstthe outer surface of the retainer ring element 111 with a flange area131 protruding radially inwards, wherein the elements 111 and 130 can bemoved against each other in an axial direction.

An energy storage 137 operates between the flange element 119 and theflange area 131, wherein said energy storage pushes parts 130 and 113apart axially and preferably is in the form of a spring inserted in aninner bore hole 133 that opens towards the top of the flange area 131.

The die insert 105 comprises a bevel 140 that tapers conically towardsits lower end, wherein said die insert is supported by correspondingbeveled areas 144 of the annulus elements 104 of the stamping element103, which run at an incline inward and outward as is explained in moredetail below.

The lower end areas of the annulus elements 104 comprise protrusions 144that protrude radially outwards in order to produce undercuts 11 in thegrooves 150 that extend radially inward and run axially. A protrudingshoulder 147 that interacts with the ironing area 107 in a way that willbe explained in more detail below connects to each annulus element 104in an axial direction on the side that faces the lateral ring element120, i.e. upward.

The extrusion device described above is processed in the followingmanner. First a sliding sleeve 1 produced by means of the methoddescribed above, comprising an inner toothing is positioned on thematrix element 101 and is ironed during the lowering of the stampingelement 103 together with the die insert and the elements 120, 109, 113,and 111 into the opening 155 of the matrix elements 101 via ironing area107 that tapers conically inwards and downwards. This means that theannular body of the sliding sleeve 1 is thinned, whereby the outerdiameter of the body, beginning at the lower end, is continuouslydecreased and the displaced material flows radially into the grooves 150of the annulus elements 104 of the stamping elements 103, wherein saidannulus elements are securely pressed against the die insert 105. To bemore exact, the bevels 140 and 142 lie against one another.

In its circumferential direction, the sliding sleeve 1 is designed insuch a way that one toothing element 5 is assigned to one groove 150 inwhich the undercuts 11 are produced, and that the transitional areasbetween two adjacent annulus elements 104 are arranged at such distancesbetween two adjacent toothing elements 5 as to allow the annuluselements 104 to move radially.

In the ironing process, the material that flows into the grooves 150assigned to the individual toothing elements 5 conforms to the shape ofthe protrusions 144 arranged in the grooves 150, which are the sameshape as the undercuts 11 that are to be produced. As is shown in thediagram of FIG. 8 using the example of two toothing elements 5, thegrooves 150 are measured with regard to the toothing elements 5 in sucha way that they are able to accept the material that is displaced andflows into the grooves 150 during ironing on the beveled surface of theironing area 107 as well as the material that is displaced at theprotrusions 133.

Once the undercuts 11 are produced in the toothing elements 5, in orderto remove the sliding sleeve 1 from the mold, the die insert 105 ispulled upwards together with the elements 120 and 109, wherein thebevels 140 and 142 separate from one another and the annulus elements104 move radially inwards, as is shown by the arrow R1. The undercuts 11are then released from the protrusions 144 and the stamping element 103is caused to move abruptly upwards together with the elements 111 and113 by the spring 133 that was previously biased by the downward motionof the die insert 105 and the elements 120, 119 130. The sliding sleeve1 can then be ejected upward by the ejector 102 in the direction of thearrow R2.

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

1. A method for producing an annular element having an inner toothing,comprising: arranging an outlet ring element in an extrusion devicewhich includes an annular matrix element with an inner bore hole, asleeve stamping device which is arranged therein and has a first and asecond annular sleeve stamping element which can be moved in relation toeach other in the inner bore hole, and an inner stamping device having afirst and a second inner stamping element and first and second partialregions which are interspaced in the circumferential direction; when theinner stamping device is closed, said partial regions forming cavitiesfor producing the inner toothing; and the outlet ring element beingarranged between the first and second inner stamping elements andmeasured in such a way that when closing the sleeve stamping device,material from the outlet ring element flows into the cavities for theformation of the inner toothing.
 2. The method according to claim 1,wherein an element in the form of a forged blank is used as the outletring element.
 3. The method according to claim 2, wherein the blank isblasted and annealed.
 4. The method according to claim 1, wherein thefirst inner stamping element and the second inner stamping element havetoothings that become meshed together so that the first inner stampingelement and the second inner stamping element are brought into an exactaxial and circumferential direction in relation to one another.
 5. Themethod according to claim 1, wherein the first partial region isdesigned and used to form a straight-cut toothing and a roof-shapedtoothing of a toothing element of the inner toothing, and a secondpartial region is designed and used to create a roof-shaped toothing ofa toothing element of the inner toothing.
 6. The method according toclaim 1, wherein the outlet element is arranged between pressingsurfaces of the first stamping element and the second stamping element,which are arranged transversely to a longitudinal axis.
 7. The methodaccording to claim 1, wherein the inner diameter, the outer diameter andthe axial length of the outlet ring element are measured in such a waythat when closing the sleeve stamping device, the outlet ring element isshortened on one end so that the material that is thereby displacedflows into the cavities.
 8. The method according to claim 1, whereinwhen closing the sleeve stamping device, the position of the firstsleeve stamping element or the second sleeve stamping device remainsstatic in its position and the second sleeve stamping device or thefirst sleeve stamping device is moved.
 9. The method according to claim1, wherein the method is carried out while the temperature of the outletring element is between ambient temperature and approximately 1200° C.10. The method according to claim 1, wherein the overflowing materialand/or burrs created during the production of the annular element areremoved by means of deburring.
 11. The method according to claim 1,wherein phosphate layers and/or rust is removed from the annual elementsby means of debonders.
 12. An extrusion device comprising an annularmatrix with an inner bore hole, a sleeve stamping device which isarranged therein and includes a first and a second annular sleevestamping element which can be moved in relation to each other in theinner bore hole, and an inner stamping device having a first and asecond inner stamping element and first and second partial regions whichare interspaced in the circumferential direction; said partial regionsforming cavities for producing an inner toothing when the first and asecond inner stamping elements of the inner stamping device are closed;and an outlet ring element being arranged between the first and secondinner stamping elements and being measured in such a way that whenclosing the sleeve stamping device, material from the outlet ringelement flows into the cavities for the formation of the inner toothing.13. The device according to claim 12, wherein the first inner stampingelement and the second inner stamping element have toothings that becomemeshed together so that the first inner stamping element and the secondinner stamping element are brought into an exact axial andcircumferential direction in relation to one another.
 14. The deviceaccording to claim 12, wherein the first partial region is designed andused to form the straight-cut toothing and roof-shaped toothing of atoothing element of the inner toothing, and a second partial region isdesigned and used to create the upper toothing of a toothing element ofthe inner toothing.
 15. The device according to claim 12, wherein thefirst sleeve stamping element and the second sleeve stamping elementhave pressing surfaces running transversely to the longitudinal axis,between which the outlet element can be arranged.